• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.352.2-352.2
• /
• 2014

In this present work, we report a Cu-Mn alloy as a materials for the self-forming barrier process. And we investigated diffusion barrier properties of self-formed layer on low-k dielectrics with or without UV curing treatment. Cu alloy films were directly deposited onto low-k dielectrics by co-sputtering, followed by annealing at various temperatures. X-ray diffraction revealed Cu (111), Cu (200) and Cu (220) peaks for both of Cu alloys. The self-formed layers were investigated by transmission electron microscopy. In order to compare barrier properties between Mn-based interlayer interlayer, thermal stability was measured with various low-k dielectrics. X-ray photoelectron spectroscopy analysis showed that chemical compositions of self-formed layer. The compositions of the Mn based self-formed barriers after annealing were determined by the C concentration in the dielectric layers.

• Journal of Sensor Science and Technology
• /
• v.15 no.5
• /
• pp.352-356
• /
• 2006

In this paper, we developed enzyme electrode of a new form to improve performance of disposable glucose sensor. We could fabricate electrode of Cu/Ni/Au structure which has very low electrical resistance (0.1 $\Omega$) by sticking copper film to plastic film with laminating method and electro-plated nickle and gold on it. The enzyme electrode was completed by immobilizing enzyme on the fabricated electrode. The fabricated glucose sensor has very quick sensing time as 3 seconds, and excellent reproducibility, fabrication yield as well.

• Journal of environmental and Sanitary engineering
• /
• v.4 no.1 s.6
• /
• pp.53-60
• /
• 1989

This study was performed to investigate the contents of heavy metals in Anguilla japonica habiting in Korea. The samples were collected along by Nak Tongriver, Young San river and culture farms. Lead, Cadmium, Copper, Zinc, Manganese, Chromium were tested by the Atomic Absoption Spectrop-hotometer after wet digestion, Mercury was tested by using mercury analyzer. The results were as follows: 1. Aresenic, Copper contents in the four parts were the higest values in liver 2. In total mercury contents of the each parts, the higest value was detected in muscle. 3. In all metals, Zinc and Manganese were detected with high contents, Mecury and Cadmium were detected with low contents. Lead, Cadmium, Zinc, chromiumi, Manganese were detected with high in bone. 4, The difference was not significant between natural and feeding Anguilla Japonica, but significant correlation with parts.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.3-6
• /
• 2003

We have developed a small-sized superconducting magnetic energy storage (SMES) device, which provides electric power with high quality to sensitive electric loads. In large magnets such as the SMES magnets the stability, which is determined by several factors, e.g. conductors cooling condition and operating current, magnets winding structure, is a crucial problem. The effect of the cooling condition, the copper ratio, and the conductor's size upon the recovery currents was investigated experimentally. The results indicate that the recovery current characteristics of the strands vary considerably according to their insulation method. In the fully insulated strands with a low copper ratio, the recovery current densities range from 10 to 20 % of their engineering critical current densities. The recovery current density of the 30-conductor with a cooling channel is about a factor of 1.8 higher than that without a cooling channel.

• Journal of the Korean Chemical Society
• /
• v.13 no.4
• /
• pp.309-312
• /
• 1969

A series of metal ion-2, 5-diamine 1, 4-dihydroxybenzene polymers containing copper(II), nickel(II) or cobalt (II) have been prepared. The structure was postulated on the basis of elementary analysis of polymers. It was found that copper polymer is most likely the coordination polymers by X-ray powder pattern studies. The thermal stability of the polymers was also studied by a simple method, utilizing a thermogravimetric balance. The order of thermal stabilities is Cu(II) > Ni(II) > Co(II). The polymers start to decompose at a relatively low temperature.

• Journal of Powder Materials
• /
• v.25 no.1
• /
• pp.19-24
• /
• 2018

Cu-Fe alloys (CFAs) are much anticipated for use in electrical contacts, magnetic recorders, and sensors. The low cost of Fe has inspired the investigation of these alloys as possible replacements for high-cost Cu-Nb and Cu-Ag alloys. Here, alloys of Cu and Fe having compositions of $Cu_{100-x}Fe_x$ (x = 10, 30, and 50 wt.%) are prepared by gas atomization and characterized microstructurally and structurally based on composition and powder size with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Grain sizes and Fe-rich particle sizes are measured and relationships among composition, powder size, and grain size are established. Same-sized powders of different compositions yield different microstructures, as do differently sized powders of equal composition. No atomic-level alloying is observed in the CFAs under the experimental conditions.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.5
• /
• pp.93-98
• /
• 2013

Fuel gas is an important energy source that is being increasingly used because of the convenience and clean energy provided. Natural gas is supplied to consumers safely through an underground gas-pipe network made of a polyethylene material. In electrofusion, which is one of the joining methods used, copper wire is used as the heating wire. However, it takes a long time for fusion to occur because the electrical resistance of copper is low. In this study, therefore, electrofusion was conducted by replacing the copper heating wire with carbon fiber to reduce the fusion time and improve the production when joining large pipes. Fusion and tensile tests were performed after the electrofusion joint was made in the polyethylene pipe using carbon fiber. The results showed that the fusion time was shorter and the temperature inside the pipe was higher with an increase in the current value. The ultimate tensile strength of specimens was higher than that of virgin polyethylene pipe, except for polyethylene pipes joined using a current of 0.8 A. The best fusion current value was 0.9 or 1.0 A because of the short fusion time and lack of transformation inside the pipe. Thus, it was shown that carbon fiber can be used to replace the copper heating wire.

• Restorative Dentistry and Endodontics
• /
• v.16 no.1
• /
• pp.6-15
• /
• 1991

The purpose of this study was to observe in vitro chloride corrosion behavior from 5 kinds of amalgam (Caulk spheracal, Amalcap, Dispersalloy, Tytin, Sybralloy) as a function of time after tritruration by using potentiostat. After each amalgam alloy and Hg was triturated as the direction of the manufacturer by the mechanical amalgamator, the triturated mass was inserted the cyrindrical matal mold ($12{\times}10mm$) and was condensed by using routine manner. The specimen was removed from the mold and was stored at room temperature for 1 week, 1 month and 3 months, and standard surface preparation was routine carried out. The 0.9% saline solution was used as electrolyte in pH 6.8~7.0 at $30{\pm}0.5.^{\circ}C$. The open circuit potential was determined after 30 minutes' immersion of 1 week, 1 month and 3 month old specimens. The scan rate was 1 mV/sec and the surface area of amalgam exposed to the solution was $0.65\;Cm^2$ for each specimen. All potentials reported are with respect to a silver / silver chloride electrode (SSE). The following result was obtained. 1. All amalgam specimens became more noble corrosion potentials which represent the improved corrosion resistance as the time elapsed. 2. Three kinds of high copper amalgam always exhibited more noble potential than low copper amalgam at 1 week, 1 month and 3 months. 3. Two kinds of low copper amalgam had the similar polarization curve pattern with 3 current peaks at each time period and current densities associated with these peaks were decreased as aging especially in caulk spherical amalgam. 4. All kinds of high copper amalgam had the similar polarization curve pattern with absence of prominent current peak at each time period, but the polarization curve of D amalgam had one apparent current peak at 1 week.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.546-546
• /
• 2008

Copper (Cu) Chemical mechanical polishing (CMP) has been an essential process for Cu wifing of DRAM and NAND flash memory beyond 45nm. Copper has been employed as ideal material for interconnect and metal line due to the low resistivity and high resistant to electro-migration. Damascene process is currently used in conjunction with CMP in the fabrication of multi-level copper interconnects for advanced logic and memory devices. Cu CMP involves removal of material by the combination of chemical and mechanical action. Chemicals in slurry aid in material removal by modifying the surface film while abrasion between the particles, pad, and the modified film facilitates mechanical removal. In our research, we emphasized on the role of chemical effect of slurry on Cu CMP, especially on the effect of amine functional group on removal rate selectivity between Cu and Tantalum-nitride (TaN) film. We investigated the two different kinds of complexing agent both with amine functional group. On the one hand, Polyacrylamide as a polymer affected the stability of abrasive, viscosity of slurry and the corrosion current of copper film especially at high concentration. At higher concentration, the aggregation of abrasive particles was suppressed by the steric effect of PAM, thus showed higher fraction of small particle distribution. It also showed a fluctuation behavior of the viscosity of slurry at high shear rate due to transformation of polymer chain. Also, because of forming thick passivation layer on the surface of Cu film, the diffusion of oxidant to the Cu surface was inhibited; therefore, the corrosion current with 0.7wt% PAM was smaller than that without PAM. the polishing rate of Cu film slightly increased up to 0.3wt%, then decreased with increasing of PAM concentration. On the contrary, the polishing rate of TaN film was strongly suppressed and saturated with increasing of PAM concentration at 0.3wt%. We also studied the electrostatic interaction between abrasive particle and Cu/TaN film with different PAM concentration. On the other hand, amino-methyl-propanol (AMP) as a single molecule does not affect the stability, rheological and corrosion behavior of the slurry as the polymer PAM. The polishing behavior of TaN film and selectivity with AMP appeared the similar trend to the slurry with PAM. The polishing behavior of Cu film with AMP, however, was quite different with that of PAM. We assume this difference was originated from different compactness of surface passivation layer on the Cu film under the same concentration due to the different molecular weight of PAM and AMP.

• Journal of the Microelectronics and Packaging Society
• /
• v.17 no.4
• /
• pp.95-100
• /
• 2010

LED (Light Emitting Diode) is 85% of the applied energy is converted into heat that is already well known. Lately, LED chips increasing the capacity as result delivered to increase the heat of the LED products and module that directly related to life span and degradation. Thus, in industry the high-power LED chip to control the heat generated during the course of the study and the existing aluminum, copper adhesives, and uses MLC (Metal clad laminate) structures using low-cost FR4 and copper CCL (Copper Clad Laminate) to reduce costs by changing to a study being carried out. In this study, using low-cost CCL Class, mounted 1W LED chip to analyze changes in the thermal resistance. In addition, heat dissipation in the CCL to facilitate a variety of thermal via design outside of the heat generated by the LED chip to control and facilitate the optimal structure of the heat dissipation is suggested.